The formulation of a teat dip is a complex process which requires that numerous ingredients be compatible and provide an effective product. Barrier-type teat dips and germicidal teat dips and combinations of the two are the main types of dips known. In practice, a teat is dipped into a teat dip subsequent to milking and the resulting film is allowed to remain on the teat until the next milking which is generally 8 to 12 hours later.
Although many germicides have been tried in teat dips, it is very difficult to find germicides which are satisfactory. A satisfactory germicide must be sufficiently effective in killing various microbes, provide a stable dip formulation, be nonirritating to the teat for the period during which it remains on the teat, and be relatively economical, since it is the major active ingredient in the formulation.
Some of the prior art germicides described as useful in teat dips include chlorinated cyanurates (U.S. Pat. No. 4,025,628), chlorhexidine (U.S. Pat. No. 4,434,181), alkyl quaternary ammonium salts (U.S. Pat. No. 3,993,777), iodine (U.S. Pat. No. 2,739,922) and combinations of nitroalkanols and aminocarboxylic acids (U.S. Pat. No. 4,199,602).
"Tego 51" and "Tego 51B" are germicidal products available from Th. Goldschmidt A.G. (Essen, West Germany). These products are complex mixtures of a variety of alkylamines and N-substituted glycines. Analysis conducted on behalf of the inventor has indicated that the major germicidal components present are 3-(n-dodecylamino)-propylamine and 2-[2-(n-dodecylamino)ethylamino]ethylamine.
A standard primary skin irritation test on rabbits (Draize test) run on "Tego 51" containing 9% "active ingredients" showed the product to be severly corrosive to skin. A severe erythema with eschar formation and severe edema was followed within seven (7) days by complete necrosis of the skin at the test site. Even when diluted to 1.0% and 0.5% concentrations, the "Tego 51" showed moderate to severe erythema and edema after 24 hours. Moderate necrosis was also seen at these concentrations. The above data are included in Report No. R-2846 (dated March 1969) provided by Th. Goldschmidt A. G., the manufacturer of "Tego 51".
M. Sipka, Arch. Lebensmittelhygiene, 1972, 23(8), 176-9 discloses the use of "Tego 51/15 DL" as an udder wash. Similarly, vendor literature provided by Th. Goldschmidt A. G. discloses the use of "Tego 51" as an udder wash. Use of a product as an udder wash involves contact of the product with the teat for only a short period of time on the order of seconds or at most a minute or two just prior to milking.
Germicides as obviously irritating as "Tego 51" and "Tego 51B" would not usually be considered suitable for use in a teat dip which entails prolonged contact of the germicide with the teat, even though their potency, spectrum of activity and cost make them otherwise very attractive candidates. Even more unlikely would be their use in a concentrated teat dip because of the chance of severe injury to the cow if the product was accidentally used undiluted. Surprisingly, however, a way to use these potent germicides in a teat dip suitable for daily use has been found.